This invention relates to a process for producing sliced veneer and fancy board therefrom, and more particularly to a process for producing sliced veneer of a large area which is able to cover an entire substrate in one operational step.
In conventional processes for producing sliced wood veneer to be glued on a substrate, a log is longitudinally divided into various-sized small flitches and they are subsequently each sliced by means of a slicer or a rotary lather into sheets of thin veneer. The sheets of thinly sliced veneer are cut to have a suitable width by a guillotine or the like. Before gluing the sliced veneer onto a substrate, it is usual to correct unevenness on the surfaces of the sheets of veneer and to remove oil remaining thereon in the step of dividing. lather.
According to this known process, however, the core timber f and triangular sections e of the logs (FIG. 1) wind up as scrap without being used in the sliced sheets of veneer. In addition the sides of the wood, as mentioned above, is cut off and is unavailablly, so in other words, only about 40% of the original log can be really used as a material for veneer in spite of the great value of lumber.
In addition, sliced sections of veneer of less than 0.3 mm thick are required to be patched onto the substrate and have to be cut one by one by hand in a known method and to overlap or fill in the gap in the sheets of veneer. The patching step is also effected by hand. Under present condition of such manufacturing, it can be said that 80% of the labor required throughout the process must be assigned to this patching and mending work. Such inefficiency in conventional manufacturing processes makes it necessary to store the sliced veneers which are not used under severly controlled conditions to keep them from transforming, falling into decay, or getting moldy due to changes of moisture content.
Prior to the present invention, the inventor herein made various trials and experiments to find an improved method relating to mass-producing sliced veneers of wide area and making use of available lumber, taking into account the aforementioned defects of known processes.
As an example of the inventors trials and experiments, original lumber or scrap timber was divided into a plurality of small rectangular solids or small flitches and joined together to form a laminated or composite flitch with water-resistant adhesive after drying. The laminated flitch was next boiled so that it had a moisture content more than the fiber saturation point (hereafter called the f.s.p.) and then thinly sliced by means of a slicer. However, it is well known in the field that swelling or shrinking occurs within lumber as the moisture content changes therein to less than the f.s.p. The phenomena also arose in the flitches used in this trial. Additionally, since the degree of this phenomena depends among other things upon the direction of the flitch relative to the axis of the wood, difficulty as regards warp and distortion occured in the finished veneer on account of the inner stress arising in the joined parts.
Therefore, according to the present invention, a new process has been devised in the form of an improved veneer with consideration being given to the fact that with a moisture content at or more than the f.s.p. lumber does not undergo the aforementioned phenomena of swelling or shrinking due to changes in the amount of the contained moisture. In the improved process, according to the present invention, the flitches have no difficulties as mentioned above as regards to whether they are dry or moist. Thus, no inner stress is generated or produced at the joined parts between the flitches, so that no distortion, warp, or cleavage will occur in the veneers sliced from the laminated flitch according to the present invention.
Furthermore, by making use of the aforementioned concept according. to the present invention, any sheets of veneer of wide or large area can be overlaid over a substrate by a single operational step to form a fancy board having desirable patterns of wood grain and inconspicuous joint lines. Of course veneers of narrow area may also be produced as desired.
An object of the present invention is to provide a process for industrially mass-producing sliced veneer sheets having desirable patterns and inconspicuous joint-lines in large quantities and in which the veneer sheets have a wide area large enough to cover an entire substrate in a single operational step without troublesome mending or patching as was required in gluing conventional sliced veneers.
Another object of the present invention is to provide a process for industrially mass-producing sliced veneers to be glued over an entire substrate in large quantities and in which the veneer is provided with desirable technological and esthetic patterns, for example checker patterns, mosaic patterns and so on formed by a combination of arrangements of the grain pattern of the wood.
A further object of the present invention is to provide a process for industrially mass-producing sliced veneers to be glued over an entire substrate in one operational step thereby reducing the amount of labor required.
Still another object of the present invention is to provide a process for industrially mass-producing a fancy board in a single operational step by gluing a sheet of sliced veneer of wide area onto a substrate, and without having to place in order a plurality of small sliced veneers on the substrate one by one as was required heretofore.
Other features which are considered as characteristic for the invention as set forth in the appended claims.
Although the invention is illustrated and described in relationship to specific embodiments, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.